Electronic device and method for an amplifier with resistive feedback

Abstract

An electronic device comprising an amplifier having at least a first input transistor of a first doping type. A first transistor is coupled with a channel as a feedback path between an output of the amplifier and a control gate of the first input transistor forming an input of the amplifier. A diode-coupled second transistor is coupled with a channel between a first current source and the output of the amplifier wherein a control gate of the first transistor is coupled between the first current source and the diode-coupled second transistor and the first transistor is of a second doping type which is opposite to the first doping type of the first input transistor of the amplifier.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This patent application claims priority from German Patent Application No. 10 2011 013 107.8, filed Mar. 4, 2011, which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION[0002]The invention relates to an electronic device with a resistive feedback and a method.BACKGROUND OF THE INVENTION[0003]There are numerous different applications where capacitively fed back amplifiers are required. This type of amplifier usually includes a capacitor coupled between an inverting input and the output of an operation or amplifier. Such an amplifier with a capacitive feedback requires a resistive path between the inverting input and the output of the operational amplifier in order to properly define a DC bias point of the input of the operational amplifier.[0004]FIG. 1 shows a simplified circuit diagram of a capacitively fed back non-inverting amplifier according to the prior art. There is an operational amplifier OP1 having a capa...

AI Technical Summary

Benefits of technology

This patent is about a new electronic device that can maintain its desired operating point for a wide range of input voltage levels. It uses a special circuit design that allows for a small power supply range and ensures the amplifier operates correctly. The device also includes operational amplifiers and a feedback system to improve its performance. Overall, this invention provides a more robust and efficient electronic device that can operate over a wide range of input levels.

Problems solved by technology

Accordingly, the DC operating point of the noninverting amplifier is established by resistor R. However, in integrated semiconductor circuits, the use of a resistor is not desirable in some cases due to the comparatively large area needed in order to implement the resistor and because of related parasitic capacitances.

However, this configuration has the disadvantage of this solution in that it requires a supply voltage of at least two threshold voltages of MOSFET transistors.

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